// Copyright (c) 2025 IBM Corp.
// All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package testing

import (
	"testing"

	EQ "github.com/IBM/fp-go/v2/eq"
	L "github.com/IBM/fp-go/v2/internal/monad/testing"
	O "github.com/IBM/fp-go/v2/option"
)

// AssertLaws asserts the monad laws for the Option monad.
// This function verifies that Option satisfies the functor, applicative, and monad laws.
//
// The laws tested include:
//   - Functor laws: identity and composition
//   - Applicative laws: identity, composition, homomorphism, and interchange
//   - Monad laws: left identity, right identity, and associativity
//
// Parameters:
//   - t: testing instance
//   - eqa, eqb, eqc: equality predicates for types A, B, and C
//   - ab: a function from A to B for testing
//   - bc: a function from B to C for testing
//
// Returns a function that takes a value of type A and returns true if all laws hold.
//
// Example:
//
//	func TestOptionLaws(t *testing.T) {
//	    eqInt := eq.FromStrictEquals[int]()
//	    eqString := eq.FromStrictEquals[string]()
//	    eqBool := eq.FromStrictEquals[bool]()
//
//	    ab := strconv.Itoa
//	    bc := func(s string) bool { return len(s) > 0 }
//
//	    assert := AssertLaws(t, eqInt, eqString, eqBool, ab, bc)
//	    assert(42) // verifies laws hold for value 42
//	}
func AssertLaws[A, B, C any](t *testing.T,
	eqa EQ.Eq[A],
	eqb EQ.Eq[B],
	eqc EQ.Eq[C],

	ab func(A) B,
	bc func(B) C,
) func(a A) bool {

	return L.AssertLaws(t,
		O.Eq(eqa),
		O.Eq(eqb),
		O.Eq(eqc),

		O.Of[A],
		O.Of[B],
		O.Of[C],

		O.Of[func(A) A],
		O.Of[func(A) B],
		O.Of[func(B) C],
		O.Of[func(func(A) B) B],

		O.MonadMap[A, A],
		O.MonadMap[A, B],
		O.MonadMap[A, C],
		O.MonadMap[B, C],

		O.MonadMap[func(B) C, func(func(A) B) func(A) C],

		O.MonadChain[A, A],
		O.MonadChain[A, B],
		O.MonadChain[A, C],
		O.MonadChain[B, C],

		O.MonadAp[A, A],
		O.MonadAp[B, A],
		O.MonadAp[C, B],
		O.MonadAp[C, A],

		O.MonadAp[B, func(A) B],
		O.MonadAp[func(A) C, func(A) B],

		ab,
		bc,
	)

}
